Ontario Air Brake Z Test cheat sheet
Ontario Air Brake Z Test · Keep the key ideas within reach.
Safe Driving with Air Brakes
Air brakes are not instantaneous: allow a longer following distance than with hydraulic brakes because application and release take time and pressure must build before full braking.
Use engine braking and lower gears on long downgrades; continuous service brake application overheats drums and linings, causing fade, so brake in short, firm applications and let speed recover.
Never fan or pump the brake pedal in a vehicle with air brakes; each application consumes stored air, and repeated fanning can exhaust the supply and apply the spring brakes.
If the low-pressure warning sounds while driving, stop safely as soon as possible; the spring brakes will apply automatically when pressure falls far enough, so do not continue to a distant stop.
Before descending a grade, check the pressure gauge is at normal operating range and select a gear that holds the desired speed without braking.
In cold weather, drain air tanks before driving and after each stop; moisture can freeze in lines and valves and cause brake failure.
When parking, apply the parking brake, chock wheels if on a grade, and remember that a vehicle with air brakes may roll if pressure bleeds off and the spring brakes are not fully set.
After any brake work, perform a complete leak and function test at low speed before returning to normal service; a brake that has not been tested is not known to be safe.